Well, it's finally happened. The 'megapixel myth' memo has gone around SO much that we now have people saying that pixels don't matter at all.
Uh… right.
Ok, so adding more megapixels to an iPhone wouldn't matter without making the camera (and thus the phone) thicker. I don't see that happening.
So yes, while 8 MP is perfectly fine for an iPhone, let's not all go crazy and say that megapixels are a totally meaningless number that do nothing. If you have a larger lens with a greater distance to the sensor then, yes, numbers higher than 8 do exist for a reason. Just because the iPhone isn't getting thicker doesn't mean that 12 or 24 MP cameras are a scam or something.